Plant and process for the production of oil



Feb. 6, 1962- w. J. cuLBERTsoN, JR., ErAl. 3,020,209

PLANT AND PROCESS FOR THE PRODUCTION OF O11.

2 Sheets-Sheet 1 Filed Oct. 20. 1958 uns? 8m $56 Nm w ...ne 211m P Jf 1.80 135110 Il IV m56 Een.: l n unoov. un

INVENTORS WML/AM J/snrzsom/ BY THe/yn OM i@ (VWS Feb. 6, 1962 w. J. cULBERTsoN, JR., ETAL 3,020,209

PLANT AND PROCESS FOR THE PRoDucTIoN oF on.

Filed Oct. 20. 1958 2 Sheets-Sheet 2 SHALE RSI-l f CDMBUJT/ON GASES FROM FLU/D/ZED BED CHL/616,7' BHLLS lNvENToRs Mu mM JCaLEea/v Je.

o 71E/amas D. Ns/M5 QL/orage' 3,020,209 PLANT AND PROCESSFQI? THE PRODUCTION of Nevada Filed Oct. 20, 1958, Ser. No. 768,229

25 Claims. (Cl. 202-14) This invention relates generally to a method and apparatus for producing oil from oil shale and other carbonaceous solid materials, and relates specifically to a method and apparatus for producing oil from oil shale or other solid carbonaceous material wherein the heat for the pyrolysis of the solid material'is obtained from dierently sized heat-carrying solid bodies.

In the past, the primary means for heating the solid bodies has involved the passage of heated air through a packed tower of the heat-carrying solid bodies. While this means of heating the heat-carrying bodies is conventional and is, in some respects, an excellent means of heating these solid bodies, several drawbacks are inherent in such means.

Firstly, in forcing the requisite amount of heated air through a packed tower of solid bodies, a considerable pressure is required. It is the usual practice in the pyrolysis of oil shale to combust shale coke in the presence of air to thereby provide heat for the heating of the solid bodies. The combustion step necessarily requires a large amount of air `for efficient combustion of the carbon in the shale coke. Consequently,.the large amount of air that is necessarily heated by this means requires that a high blower pressure be employed in forcing the resulting products of combustion, e.g., carbon monoxide, carbon dioxide, and water vapor, through a packed tower of solid bodies. While the heat transferred to the solid bodies, by the combustion gases in a bed depth of the extent found in the normal packed bed tower is high, this mode of heat transfer may, nonetheless, in some cases, prove unfeasible because of the abnormally high blower pressure required to force the gases through the packed tower, and because of other difficulties to be now described.

In addition to the use of hot gases for the heating of the solid bodies, it has been heretofore proposed to utilize the heat in solid particles entrained by the gases, these entrained particles usually emanating from a fluidized bed of shale coke or the like. The hot particles entrained with the hot gases are found to considerably increase the heat capacity of the heating media and to thus cause a substantial reduction in the need for any considerable contact time of such gases with the solid heat-carrying bodies. The entrained solids in the gases present further problems in the normal countercurrent packed tower method of heating the balls since frequently they will be held up by the balls. The problems of large bed depth are thus accentuated in such entrained solids processes.

Also, complex problems, attendant upon the uniform feeding and removal of the soid bodies from heating apparatus used heretofore, also severely limit the use of such apparatus. It has been found that the most effective method of obviating the problems above mentioned, is to employ a novel combined ball heating and ball feeding States arent ice device for the .solid bodies. Heretofore, the ball heating devices and the ball feeding devices, have been, to our knowledge, entirely separate and distinct devices, and have therefore necessitated a substantially greater capital eX- pense than if these pieces of equipment could be incorporated into a single unit.

.In view of the foregoing facts, it is a major object of the present invention to provide a method and apparatus for substantially reducingV the blower pressure requirements in a process which employs solid bodies as the media for the heating of oil shale and other solids leaving a carbonaceous residue upon pyrolysis.

Another object of the present invention is to provide a method and apparatus for the uniform feeding, heating and removal of heat-carrying bodies in a process wherein said solid bodies are employed to pyrolyze oil shale or the like. Y

A further object of the present invention is to provide a method and apparatus for producing oil from oil shale wherein the feeding and heating devices for solid bodies employed as the heat-carrying media in the pyrolysis of oil shale, or the like, are a novel, and relatively inexpensive, integral unit.

Yet another object of the present invention is to provide a process for combusting shale coke or the like, in a, fluidized state, and transferring the heat in the resulting combustion gases and entrained solids, to solid bodies used in the pyrolysis of oil shale, or the like, the gases and entrained solid means for heating the solid bodies requiring substantially less blower pressure than prior art means, said `solid body heating means being integrally combined with a feeding means for feeding the heated solid bodies at a predetermined rate to oil shale, or the like, for the pyrolysis thereof.

These, and other objects of the present invention, will be clearly understood by referring to the following description, and to the accompanying figures, in which:

FIGURE l is a schematic representation of a process for producing oil from oil shale incorporating our novel means for both heating and feeding the solid bodies employed in our process;

FIGURE 2 is a schematic representation of a modified form of our means for both feeding and heating the solid bodies, this modified means being incorporated into the overall process of FIGURE l, or into a similar process for producing oil from oil shale;

FIGURE 3 is a perspective view of a grate section of the continuous grate shown schematically in FIGURES l or 2;

FIGURE 4 is a side elevational view, in schematic representation, of a portion of a typical discharge or feeding device; and

FIGURES 5 and 6 are side elevational views, in schematic representation, of preferred solid bodyv discharge or feeding devices of the present invention.

In general, our invention comprises a combined solidbody heating and feeding device employed in a process for pyrolyzing oil shale or the like by means of said solid bodies. The heating and feeding device is simplified because it is an integral unit and is more efficient because it allows a reduced gas pressure to be employed in heating the solid bodies, than is ordinarily the case.

More specifically, referring to FIGURE 1, a schematic representation of one preferred form of our process, as applied to oil shale, and incorporating our improved combined ball heating and feeding device, is shown. Cold shale is introduced into a rotatable preheating drum or zone i via conduit Z-toget-her with generally spherical, heat-carrying solid bodies or balls, entering zone via line Tnt, at a higher temperature, the cold shale being thereby preheated to a temperature of preferably between 400-600 F. The incoming balls enter the zone 10 at a temperature preferably ranging between 850 and 1050 F. while the cold shale has an inlet temperature ranging between 30-l00 F. The cooled balls are then reheated for the pyrolysis step, as will be later described.

The preferred ratio between balls and oil shale ranges between 1:1 and 3:1 depending upon the nature of the balls, and the type of oil shale being processed. The balls employed are usually composed of a hard heat resistant composition such as ceramic, steel, or alumina, or a combination of these, and are generally, -though not always, of a substantially larger size than the incoming oil shale. The balls and oil shale are intimately intermixed in the rotating drum 10, and it is noted that the balls and oil shale enter the drum 10 in parallel flow, although counterflow of these materials could also be employed, if desired.

While a rotatable drum has been described for the intermixing of balls and ore, other modes of intermixing can also be used, such as a vertical mixer having vinternal mixing means.

The preheated oil shale is separated from the differently-sized balls, by conventional screening or other means (not shown), and leaves zone 10 via conduit 16 under the influence of gravity and/or conventional conveying means (not shown). The oil shale then enters a rotatable pyrolysis zone or drum 20, where it is intimately intel-mixed with hot balls entering the drum, via conduit 22 the balls being heated in a zone 40, by means to be described. The preferred temperature of the incoming balls ranges between 1000 F. and 1400" F., this temperature being found most favorable for the production of a maximum amount of oil from oil shale and the like. While parallel flow is shown, and is presently preferred, counterflow of the solid bodies and oil shale can be also employed in which case the inlet ball temperature ranges between 800 and 1200 F.

The oil vapors and gases, resulting from the pyrolysis, leave the zone `along overhead conduit 23, and are either sent directly to cracking or refining stages, or. to a condensing unit (not shown), and from the condensing unit to cracking or other refining steps. The exit temperature of the oil vapors and gases ranges preferably between 825 and 10007 F.

The balls and pyrolyzed oil shale (the pyrolyzed oil shale being sometimes termed hereinafter, and in the claims, as shale coke) leave the pyrolysis zone 20, the exit ball temperature ranging between 850 and l050 F. and the exit shale coke temperature ranging between 750 and 950 F., and are separated on the screen 24, the smaller-sized shale coke passing through the screen while the larger-sized balls are carried upwardly, by a ball elevator (not'shown) or other conventional means to the preheating drumlO, via conduit 14, for the preheating step above-described. Other conventional means of separa-tion, e.g. elutriation or magnetic separation can also be used instead of the screen 24.

During the pyrolysis, it should be noted that the balls grind and to a great extent, render iluidizable the resulting shale coke, thereby enabling ready separation of the balls and shale colte by means of the screen 24, and enabling the shale coke to be readily fluidized, without any appreciable further grinding or classification for the later combustion step to be described.

`While the preferred mode of pyrolysis of the oil shale requires that two drums be employed, one for preheat and one for pyrolysis, it is sometimes desirable to employ a single drum for both steps. In either case, the particulate shale coke, resulting from the pyrolysis, is transferred to the combustion zone 30, via line 28 by any conventional means, such as by gravity feed. It is there iluidized by means of preheated air, or other free oxygencontaining gas, entering zone 30, via conduit 32, at a ternperature ranging preferably between 600 and 1000 F. The preheated air passes lupwardly through a plate or screen 34, which is o-f sufficiently fine mesh size to render the gas passing therethrough of a higher velocity than the settling velocity of the particles.

The carbon in the shale coke is combusted by means of the oxygen-containing gas to produce extremely hot carbon monoxide, car-bon dioxide, nitrogen, water vapor and other hot gases, having a temperature ranging preferably between 1200 and l600 F. The hot gases leave the iluidized shale coke combustion bed or zone 30, via overhead conduit 36, carrying therein hot combusted shale coke or ash, also at a temperature ranging between preferably 1200 and 1600 F. The hot gases, together with the hot entrained ash, is found to substantially enhance the heat transfer to the solid bodies, in contrast with a process utilizing hot gases as the sole heating media for the solid heat-carrying bodies.

While a iluidized combustion step is preferred, it is to tbe 'understood that other types of combustion may also be employed. g

The hot entrained shale ash and combusted gases are then pa-ssed into our ball heating zone 40, Via conduit 36, the hot gases and ash flowing downwardly and through a generally horizontally moving bed of balls 43, having a bed thickness varying general-ly from 6" to 24". The balls, entering the zone 40, are the cooled balls sent from the preheating drum 10, via conduit `41, these balls having a temperature ranging between 450 and 700 F., although if the preheating drum is omitted, the balls would then come directly from the pyrolysis dnum 20.

The ball heating zone 40 comprises a housing 39, in which is mounted a continuous revolving grate 42 (revolving clockwise), thus carrying balls from the inlet end of the zone 40 to the outlet end thereof. The continuous grate 42 consists of a series of similar hinged sections 44 of perforated grating, such as shown in FIG- URE 3. The elongated holes 46 in the grate section 44 occupy preferably 25 to 50% of the surface area thereof, the width of the individual holes being such'as to allow the gases and entrained ash to readily pass therethrough, while, at the same time enabling the balls to be retained on the grate 42. The balls are prevented from falling off the sides of the grate 42 by suitable side flanges 49 attached thereto. The balls are heated to a sufliciently high temperature ranging between 1000 and 1400" F. They are then fed directly by gravity, to the pyrolysis zone 20 via conduit 22.

The somewhat cooled ash and gases continue their downward movement to a heat exchanger 50 via conduit 52, the ash and gases now having a temperature of between 800 and l200 F. A. very substantial amount of the heat in said ash and gases may be transferred to incoming cold air, entering Zone 50, via line 61, at say 30 to F., the cold air being thereby heated to a temperature of between 600 and 1000 F. 'I'he preheated air is then sent to the combustion zone 30 via conduit 32. The exhaust shale ash and gases leave the heat eX- changer via exit conduit 56, to be used for other heat or power generation purposes, or else sent to waste.

In summary, the preferred temperature ranges of the various streams for a 20-25 gallon per ton Colorado oil shale, are tabulated below-together with a tabulation of preferred operating temperatures. These ranges and temperature vary somewhat with the oil and water content of the oil shale.

Preferred Preferred Temperature Tempera- Range, F. ture, F.

I. In zone IO-Dreheating:

oil shale inlet line 12 30.- 100 50 ball inlet line 14 850-1, 050 975 oil shale outlet line 16. 400- 600 500 ball outlet line 41 450- 700 585 II. In zone 20-pyrolyslsz ball inlet line 22 1, 000-1, 400 1, 300 shale inlet line 16 400- 600 500 shale outlet line 28.- 750- 950 900 b all outlet line 14 S50-1,050 975 011 vapors and gas line 23 750- 950 900 III. In zone Sil-combustion:

shale inlet line 28 750- 950 900 preheated air inlet line 32 600-1, 000 900 shale ash and combustion gas outlet line 3 1, 20o-1,- 600 1, 400 IV. In zone Iitl-ball heating:

ball inlet line 41 450- 700 585 shale ash and combustion gas inlet line 36 1, 200-1, 600 1, '400 ball outlet line 22 1, 0004, 100 l, 300 shale ash and combustion gas outlet line A 52 t 800-1, 200 1, 000 V. In zone 50-air preheat: Y

shale ash and gas inlet line 52 800-1, 200 '1, 000 arr inlet 6l 30- 100 50 air outlet line 32 600-1, 000 900 shale ash and gas outlet line 56 Q... 300- 700 500 Turning now to FIGURE `2, another preferred embodiment of our ball heating and feeding device is shown. Generally this embodiment is termed herein as a multiple pass ball-heating and feeding device, andl differs from the embodiment shown in FIGURE l in having more than one pass of entrained ash and combustion gases moving through the packed bed 90. It is found frequently desirable to increase the eective amount of heat transferred to the balls by increasing the number of passes of shale ash and combusted gases to two, as shown in FIG- URE 2, or three or more (not shown).

The entrained shale ash and combustion gases enter the ball heating and feeding zone 92 at a high temperature, e.g. l400 F. and immediately flow across and through the moving bed of balls 90 and through the porous grate 91 (the bed thickness being approximately the same as in FIGURE 1, e.g. 0.25 to 2 feet). Baffies 94, which are usually metal flaps dragging on, or slightly clearing the top of the ball bed 90, channel the shale ash and gases downwardly and keep the gas streams of each pass separated. The gases and entrained ash then pass upwardly, through conduit 96, and downwardly a second time through the bed of incoming balls 90. The cooler gases and ash then pass outwardly through discharge conduit 98, the gases, at a reduced temperature ranging bebetween 625 and l025 F. being sent to a heat exchanger, such as Zone 50, to preheat air, or for other heating purposes. It will be noted that the hottest gases first contact the hotter balls and the cooled gases contact the cooler balls thus providing heating media which heats the balls to progressively higher temperatures as the balls -move through the heating zone 40.

The amount of heat transferred from the shale ash and gases is substantially greater in the multipass unit 92 than in the single pass unit 40, eg., the shale ash and gases leave the multipass unit 92 approximately 175 F. cooler than in single pass Zone 40. It will thus be seen that the multipass heating of the balls being more efcient heat-transfer-wise, requires less gas volume and consequently requires still less blower power than the form shown in FIGURE l. Of course, an economic balance will have to be made to determine which embodiment to use since the FIGURE 1 embodiment is a less expensive unit.

The ball heating means 92 of FIGURE 2, when employed, replaces the ball heating zone 40 in its entirety. Thus the ball discharge line 22 is connected to the outlet end of the ball heating zone 92 and the ball inlet line 41 of FIGURE l is connected to the inlet side thereof.

Attention is also directed -to the fact that .the ash and gases ilow preferably downwardly but upward flow is also utilized when the -ash is iinely divided and the gas temperature does not harm the grate. In each pass in either the FIGURE 1 or 2 embodiment, the gas and ashes are blown downwardly through the moving bed of balls rather than in an upwardly direction. This downdraft method of blowing the .heating media more effectively enables the passage of the `ash -particles through the interstices of the balls and reduces the possibility of ash-hold-up. Another advantage of downward blowing is that the grate material is not heated to as high a temperature, inasmuch as the hot gases and ash irst impart their heat to the moving bed before contacting the grate means, 42 or 91, itself.

It will be noted that in either the FIGURE l or 2 embodiment, the heat-carrying balls can be heated to proper temperature and can be fed, at the desired rate, to the pyrolysis drum 20 merely by varying thepbed depth or by varying the rate of travel of the grate 42, or both.

It should. also be noted that the use of the continuous grate means for heating a certain amount of balls per unit 'of time'enables the feedingof a designated amount of balls per unit of time `from the preheating zone 10 to the pyrolysiszone 20 Without the need Vfor any additional metering or ball control equipment. The cooled balls in line 41, are simply fed, by gravity, onto the grate 42 or 91,

and are conveyed, at a speoied rate (and bed depth), to the pyrolysis drum 20, being heated to the desired temperature `during its travel through the zone or 92. respectively.

The requirements imposed upon the blower 60 are vdependent to a great extent upon the resistance presentedv by the packed moving Abed 43, or of balls in the ball heating zones 40 or 92. In a balllheating tower, wherein the gases pass countercurrently through downwardly moving balls, the pressure requirements for the blower 60 are comparatively great because of the length of the bed. Also, channelling of the balls in the ball tower becomes a serious problem inasmuch -as the diameter of the ball tower must be relatively large compared to the inlet and outlet openings thereof. 'Il-lis means that the balls at the periphery of the ball tower are held up and become overheated. From the point of View of yheat transfer requirements, however, a relatively minor bed depth, compared to that usually employed in a ball heating tower, is highly satisfactory in the pyrolysis of oil shale and the like. Also, because of the cross-flow of gases and ash to balls and the relatively minor bed depth (which varies preferably between limits of 0.25 feet and 2 feet), the pressure drop through the bed is greatly reduced. And further, the heat transferred Ito all ythe balls is substantially more uniformly distributed than in the yball tower thus resulting in a more uniform ball exit temperature.

In the past, adequate ball feeding and control devices have either been unduly complex, or have not functioned Well. The continuous grate means 42, however, provides a comparatively simple and efficient combined heat-regulating and feed-regulating device for ourprocess.

A portion of a typical grate 42' is shown in FIGURE 4, each grate section having vertical end faces 45. As the gra-te sections turn around the pulley 74, the balls carried on the grate sections may slip between the sections and get caught. 'llhe balls are thus frequently held between adjacent grate sections 70, 72 as they turn about the pulley 74, as shown in FIGURE 4.

In FIGURES 3 and 5, one means for avoiding such ball hold-up is shown. Here the grate sections 76 -are rhombic shaped, the end faces 77, being sloped obliquely to the top surface 77 of the grate sections, thereby enabling release of the balls much sooner than in the typical grate section of FIGURE 4 as they turn, and enabling any balls getting caught between the grate sections to rolloif, as they round the pulley 74.

A further. embodiment of a continuous grate 7S is shown in FIGURE 6, each grate section 84D thereof being somewhat S-shaped, and overlapping the inmediately adjacent section. In this way, the balls are prevented from being caught between the grate sections as they'turn about the pulley 82.

While several embodiments of our invention 'have been shown and described therein, it will be understood that changes and modification may be made that lie within the scope of the invention. Therefore, we intend to be bound only by the appended claims.

We claim:

1. A process for producing oil and gas from solid material leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said solid material to produce oil vapors and gases, and a solid carbonaceous residue, heat `for said pyrolysis step being provided by admixture of said solid material with solid heat-carrying bodies; combusting said solid carbonaceous residue, produced upon pyrolysis of said solid material, by means of la free oxygen-containing gas to thereby produce heat in the form of hot gaseous products, Vand solid products entrained therein; continuously passing solid bodies, inthe form of a bed of shallow thickness, through at least a portion of said products of combustion whereby to re-heat said solid bodies; and repeating said pyrolyz-ing step by admixture of additional solid material with said reheated solid heat-carrying bodies.

2. The process of claim 1 wherein said solid material is first preheated by means of solid heat-carrying bodies in a separate zone.

3. Approcess for producing oil and gas from solid material leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said solid material to produce oil vapors and gases, and a solid carbonaceous residue, heat for said pyro-lysis step being provided by admixture of said solid material with solid heat-carrying bodies; combusting said solid carbonaceous residue, produced upon pyrolysis of said solid material, by means of a free oxygen-containing gas to thereby produce heat in the form of hot gaseous products, and solid products carried therein; continuously passing solid bodies, in the form of a generally horizontal bed of shallow thickness, through at least a portion of said products of combustion whereby to re-heat said solid bodies; and repeating said pyrolyzing step by admixture of additional solid material with said reheated solid heat-carrying bodies.

4. The process of claim 3 wherein said solid carbonaceous residue is combusted in a fluidized state.

5. A continuous process for producing oil and gas from solid material leaving, upon pyrolysis, a solid 'carbonaceous residue, which comprises the steps of continuously pyrolyzing said solid material to produce oil vapors and gases, and a solid carbonaceous residue, heat for said continuous pyrolysis step being provided by continuous admixture of said solid material with solid heat-carrying bodies; combusting said solid carbonaceous residue, produced upon pyrolysis of said solid material, by means of a free oxygen-containing gas to thereby produce heat in the form of hot :gaseous products, and solid products entrained therein; continuously passing solid bodies, in the form of a generally horizontal continuously moving bed of shallow thickness, through at least a portion of said products of combustion whereby to reheat said solid bodies, said bed. of solid bodies moving at a constant rate therethrough; and feeding said reheated bodies, at said constant rate, to additional solid material for the pyrolysis thereof.

6. A continuous process for producing oil and gas from solid material leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: continuously pyrolyzing said solid material to produce oil vapors and gases, and a solid carbonaceous residue, heat for said continuous pyrolysis step being provided by continuous admixture of said solid material with solid heatcarrying bodies; uidizing said solid carbonaceous residue; combusting said solid carbonaceous residue in said uidized state, to thereby produce gaseous products of combustion and hot solid products of combustion carried therein; continuously passing said solid bodies, in the form of a generally horizontal bed of shallow thickness, through said hot gaseous and entrained solid products of combustion whereby to reheat said solid bodies, said bed of solid bodies moving at a constant rate therethrough; and feeding said reheated solid bodies, at said constant rate, to additional solid material for the pyrolysis thereof.

7. The process of claim 6 wherein said solid bodies move, in cross-How, through said hot gaseous and solid products of combustion and said solid bodies and said solid material move in parallel flow during pyrolysis,

8. The process of claim 6 wherein said hot gaseous and solid products of combustion move downwardly, in crossow, through said solid bodies, and lsaid solid bodies and said solid'material move in parallel-now during pyrolysis.

9. The process of claim 6 wherein said solid bodies are reheated by passing said hot gaseous and solid products of combustion downwardly, in cross-ow, through said solid bodies more than once, and said solid bodies and said solid material move in parallel ow during pyrolysis.

10. A process for producing oil and gas from oil shale leaving, upon pyrolysis, a solid carbonaceous residue, which comprises the steps of: pyrolyzing said oil shale to produce oil vapors and gases, and a solid carbonaceous residue, heat for said pyrolysis step being providedl by admixture of said oil shale with solid heat-carrying bodies; combusting said solid carbonaceous residue, producedV upon pyrolysis of said oil shale, in the presence of airto thereby produce heat in the form of hot gaseous prod-` ucts and solid combusted products entrained therein; con-- tinuously passing solid bodies, in the form of a generallyv horizontal bed of shallow depth,'in cross-flow, through at least a portion of said products of combustion whereby' to re-heat said solid bodies; and repeating said pyrolyzing step by admixture of additional oil shale with saidI reheated solid heat-carrying bodies.

11. The process of claim 10 wherein said solid carbonaceous residue is iluidized and combusted by said air in said fluidized state.

12. The process of claim l() wherein said solid carbonaceous residue is fluidized, and combusted in said fluidized state by said air, and said products of combustion are passed downwardly, in cross-flow through said moving solid bodies, more than once to thereby reheat said heat-carrying solid bodies.

13. A continuous process for producing oil and gas from particulate oil shale leaving, upon pyrolysis, shale coke, which comprises the steps of: continuously pyrolyzing said oil shale to produce oil vapors and gases, and particulate shale coke, heat for said continuous pyrolysis step being provided by continuous admixture of said oil shale with solid heat-carrying bodies; iiuidizing and combusting said particulate shale coke produced upon pyrolysis of said solid material, by means of air to thereby produce heat in the form of hot gaseous and solid ash products; continuously reheating said solid bodies in a heating zone, said solid bodies passing through said heating zone in the form of a generally horizontally moving packed bed of shallow depth, said bed of solid bodies being heated by cross-flow contact with said gas and solid ash products of combustion entrained therein; and repeating said pyrolysis step by continuous admixture of additional oil shale with said reheated solid heat-carrying bodies.

14. The continuous process of claim 13 wherein said packed bed of solid bodies moves at a constant rate, and said reheated solid bodies are continuously fed, at said constant rate, to additional oil shale for the pyrolysis thereof;

9, 15. A process for producing cil and gas from oil shale leaving, upon pyrolysis, shale coke which comprises the steps of: pyrolyzing said oil shale to produce oil vapors and gases, and shale coke, heat for said pyrolysis step being provided by admixture of said oil shale with solid heat-carrying bodies; combusting said solid shale coke produced upon pyrolysis of said oil shale, in the presence of a free oxygen-containing igas to thereby produce heat in the form of hot gaseous and entrained solid products; collecting solid bodies, which` have previously imparted their heat for the pyrolysis, into a generally horizontal |bed of shallow thickness of between 0.25 and 2 feet; transferring at least a portion of the heat in said products of combustion to said bed of solid bodies by passing said products of combustion therethrough in cross-flow; and repeating said pyrolyzing step by admixture of additional oil shale with said reheated solid heat-carrying bodies.

16. A process for producing oil and gas from oil shale `leaving, upon pyrolysis, a solid carbonaceous residue,

which comprises the steps of: pyrolyzing said oil shale to produce oil vapors and gases, having a temperature of between 750 and 950 F., and a solid carbonaceous residue, heat for said pyrolysis step being provided by admixture of said oil shale with solid heat-carrying bodies; combusting said solid carbonaceous residue, produced upon pyrolysis of said solid material, in the presence of a free oxygen-containing gas to thereby produce heat in the form of hot gaseous and solid products entrained therein, the temperature of products of combustion ranging between 1200 and 1600 F.; continuously passing solid bodies, in the form of a generally horizontal bed of shallow depth, through at least -a portion of said products of combustion whereby to re-heat said solid bodies to between 800 and 1400 F.; and repeating said pyrolyzing step by admixture of additional oil shale with said reheated solid heat-carrying bodies.

17. The process of claim 16 wherein said solid bodies are reheated to a temperature of between 1000 and 1400" F. and are admixed in parallel ilow with additional oil shale.

18. The process of claim 16 wherein said oil shale is preheated to between 400 and 600 F. by means of hotter heat-carrying solid bodies in a separate zone from the pyrolysis zone.

19. Apparatus for heating solid heat-carrying bodies, which comprises: a housing having an inlet land an outlet end; continuous grate means containing a shallow layer of solid heat-carrying bodies, the said grate means consisting of a series of hinged grate sections in which adjacent grate sections overlap each other, for conveying said solid heat-carrying bodies from said inlet to said outlet end of said housing, each of the grate sections of said grate means having a plurality of openings therein, the openings having at least one dimension smaller than said heatcarrying bodies; and means for continuously passing gaseous and entrained solid heating media, in cross-flow, through said grate sections whereby to heat said solid bodies carried thereon.

20. In a plant for the pyrolysis of particulate solid material, leaving a carbonaceous residue, by means of heated solid bodies, said plant having a rotatable pyrolysis drum, means for feeding solid material into said pyrolysis drum, and means in said pyrolysis drum for discharging oil vapors and gases produced during pyrolysis, the improvement which comprises: a moving grate for feeding said solid 'bodies to said rotatable pyrolysis drum; means for passing hot gases, having hot entrained solids therein, Y

in cross-110W, downwardly through said solid bodies being carried on said moving grate, said grate having openings therein whereby said gases and entrained solids will pass substantially completely therethrough.

21. In a plant for the pyrolysis of particulate solid material, leaving a carbonaceous residue, by means of heated solid bodies, said plant having a preheating chamber, a pyrolysis chamber and means in said pyrolysis chamber for discharging oil vapors and gases produced during pyrolysis, and means for combusting said carbonaceous residue to produce hot gases having hot entrained solids therein, the improvement which comprises: a continuously moving grate `for feeding said solid bodies from said preheating chamber to said pyrolysis chamber; and means for passing said hot gases, having hot entrained solids therein, downwardly through said solid bodies While they are moving on said continuous grate, said grate having openings therein whereby said gases 'and entrained solids will pass substantially completely therethrough.

22. In a plant for the pyrolysis of particulate solid material, leaving a carbonaceous residue, by means of heated solid bodies, said plant having a rotatable preheating drum, a rotatable pyro-lysis drum, means in said pyrolysis drum for discharging oil vapors and gases produced during pyrolysis, and means for combusting said carbonaceous residue to produce hot gases having hot entrained solids therein, the improvement which comprises: a moving continuous grate for feeding said solid bodies from said preheating drum to said rotatable pyrolysis drum;

and means for passing said hot gases, having hot entrained solids therein, downwardly through said solid bodies while they are moving on said continuous grate, said grate having openings therein whereby said gases and entrained solids will pass substantially completely therethrough.

23. In a plant for the pyrolysis of particulate solid material, leaving a carbonaceous residue, which has a rotatable solid material preheating drum, inlet means in said preheating drum for solid material and solid heat` carrying bodies, outlet means in said preheating drum for said solid material and said bodies, a rotatable pyrolysis drum, inlet means in said pyrolysis drum for solid bodies and preheated particulate solid material, outlet means for oil vapors, gases, carbonaceous shale residue, and solid bodies, and means for combusting the carbonaceous shale residue to produce hot solid and gaseous products of combustion, the improvement which comprises: a grate moving continuously and at a constant rate, for feeding said solid bodies from said preheating drum to said rotatable pyrolysis drum; means for passing said hot solid and gaseous products of combustion in cross-flow, downwardly through said solid bodies while they are moving on said continuous grate, said grate having openings therein whereby said gases and entrained solids will pass substantially completely therethrough.

24, A plant for t-he pyrolysis of particulate solid material, leaving a carbonaceous residue, which comprises: a rotatable preheating drum; inlet means in said preheating drum for solid material and hotter solid heatcarrying bodies; outlet means for said solid material and said bodies; means for feeding said solid material and said solid bodies to a rotatable pyrolysis drum and continuously moving grate respectively; means for passing hot gases, having hot entrained solids therein, downwardly through said solid bodies being carried on said continuous grate, said grate having openings therein whereby said gases and entrained solids will pass substantially completely therethrough and heat said solid bodies, said grate being arranged and moving at such a rate that said solid bodies are fed into said pyrolysis drum for the pyrolysis of solid material; conduit means for discharging oil vapors and gases produced during pyrolysis; means for transferring said solid bodies, after pyrolysis, to said solid body inlet means of said preheating drum; mean for transferring carbonaceous solid residue produced during pyrolysis to a combustion chamber; blower means for introducing gas into said combustion chamber to iluidize said residue and to support the combustion 1 1 to said continuous grate for the reheating of the carried thereon.

25. A plant for the pyrolysis vof particulate'solid material, leaving a carb-onaceous residue, which comprises: a rotatable preheating drum; inlet means in said preheating balls drum for solid material and hotter solid heat-.carrying bodies; outlet means for said solid material and said bodies; a first and second conduit means `for feeding said solid material and said solid bodies, to a rotatable pyrolysis drinn and continuously moving grate, respectively; a 10 third conduit means for passing hot gases, having hot entrained solids therein, in cross-flow, downwardly through said solid bodies being carried on said continuous grate, said grate having openings therein whereby said gases and `entrained solids will pass vsubstantially completely therethrough, said grate 'being arranged and moving Vat such a rate that said solid bodies are fed directly to said pyrolysis -drum for the pyrolysis of said preheated solid material; a fourth conduit means for discharging oil vapors and gases produced during pyrolysis; means for transferring said solid bodies, after pyrolysis, to' said solid body inlet means of said preheating drum; means for transferring carbonaceous solid residue produced during pyrolysis to a combustion chamber; means for introducing gas into said combustion chamber to uidize said residue and to support the combustion thereof, said combustion producing hot Combustion gases and `eombusterd residuey which are transported through said third conduit means to said continuous grate for the reheating of the bodies carried thereon.

References Cited in the tile of this patent UNITED STATES PATENTS 1,712,083 Koppers May 7, 1929 2,664,715 Atwell Dec. vl5, 1936 2,420,376 Johansson May 13, 1947 2,743,216 Jahnig-et al Apr. 24, 1956 2,776,935 Jahnig et al Ian. 8, 1957 

1. A PROCESS FOR PRODUCING OIL AND GAS FROM SOLID MATERIAL LEAVING, UPON PYROLYSIS, A SOLID CARBONACEOUS RESIDUE, WHICH COMPRISES THE STEPS OF: PYROLYZING SAID SOLID MATERIAL TO PRODUCE OIL VAPORS AND GASES, AND A SOLID CARBONACEOUS RESIDUE, HEAT FOR SAID PYROLYSIS STEP BEING PROVIDED BY ADMIXTURE OF SAID SOLID MATERIAL WITH SOLID HEAT-CARRYING BODIES; COMBUSTING SAID SOLID CARBONACEOUS RESIDUE, PRODUCED UPON PYROLYSIS OF SAID SOLID MATERAIL BY MEANS OF A FREE OXYGEN-CONTAINING GAS TO THEREBY PRODUCE HEAT IN THE FORM OF HOT GASEOUS PRODUCTS, AND SOLID PRODUCTS ENTRAINED THEREIN; CONTINUOUSLY PASSING SOLID BODIES, IN THE FORM OF A BED OF SAHLLOW THICKNESS, THROUGH AT LEAST A PORTION OF SAID PRODUCTS OF COMBUSTION WHEREBY TO RE-HEAT SAID SOLID BODIES; AND REPEASTING SAID PYROLYZING STEP BY ADMIXTURE OF ADDITONAL SOLID MATERIAL WITH SAID REHEATED SOLID HEAT-CARRYING BODIES. 